The FBI has been working on multiple investigations into alleged connections between Russia and Donald Trump, his presidential campaign or its supporters, but so far, no probe has yielded proof of criminal connections between them, according to CNN.

U.S. law enforcement and intelligence officials believe the hacks of Democratic Party organizations involve Russian spy agencies trying to stir up confusion, rather than trying to help one of the presidential candidates.

The FBI has been looking into connections of the Republican presidential candidate's former campaign manager Paul Manafort and his firm's connection to Putin supporters in Ukraine. Other firms in the probe include the Podesta Group, which is run by Tony Podesta, brother of Hillary Clinton's campaign manager, John Podesta, according to another report on CNN.

The Bureau has looked into meetings that were allegedly between ex-Trump adviser Carter Page in Russia related to individuals that have been under U.S. sanctions, as well as allegations against Trump supporter Roger Stone in connection with WikiLeaks.

Democrats have claimed Stone conspired with WikiLeaks to coordinate the distribution of Democratic Party officials' hacked emails.

Stone has denied the accusations, but told Miami's CBS 4 News he has "back-channel communications" with the hacking group and a mutual friend with its founder Julian Assange.

The FBI and Justice Department have met with difficulty in WikiLeaks investigations because of First Amendment protections. The FBI has not been able to prove WikiLeaks is conspiring with Russian intelligence.

The New York Times also reported the FBI has found no criminal links between Trump and Russia.

Mother Jones reported on possible connections between Trump and Russia: a former counterintelligence specialist told Mother Jones he provided the FBI with memos that show the Russian government has tried to co-opt and assist Trump.

The FBI has been working on multiple investigations into alleged connections between Russia and Donald Trump, his presidential campaign or its supporters, but so far, no probe has yielded proof of criminal connections between them, according to CNN.